Tag Archives: Electromagnetic radiation

I, like many aging rockers, proudly wear my Pink Floyd Dark Side of the Moon T shirt around the house.

So the question is, could a pupil wear this in a GCSE physics exam, and would it be of any use?

The answers are possibly, and yes.

Most pupils have to wear school uniform in GCSE exams, but it is possible some don’t (think re-takers or adult education). But it is likely they would have to change or cover up, as “notes that would help” are precluded. If however all those barriers were crossed, would it actually be of use? The answer is definitely yes. Useful both to you – and here’ s the catch – everyone else!

A very typical Physics GCSE question might be to predict and explain the path of white light entering a prism, and what would the positions of red and violet light be?

The T-shirt goes a long way to answering the question.

White light disperses as it enters a prism because different wavelengths of light refract by different amounts. Unlike a rectangular block, the boundaries of a prism are not parallel so the different colours of different wavelengths do not recombine.

But why is red at the top of the spectrum and violet at the bottom, and how do you remember which way round it is? Well, red has the longest wavelength of the visible part of the electromagnetic spectrum and is refracted i.e. bent the least, whereas violet has the shortest wavelength and is bent the most.

How could you remember this? For the exam you certainly need to learn the key parts of the whole of the electromagnetic spectrum from radio waves down to gamma waves; and within that, the order of the visible light colours – but how to do that?

Well, you could wear the T shirt and be asked to leave the exam room. or use a technique close to the Mathemeteer’s heart – the mnemonic (always wondered how to spell that!)

Richard of York Gave Battle in Vain RedOrangeYellowGreenBlueIndigoViolet!